Continuous metal press



p 33- c. E. BENNETT 1,926,666

CONTINUOUS METAL PRESS Filed Feb. 1, 1932 2 Sheets-Sheet 1 IN V EN TOR.

ATTORNEYS.

Sept. 12, 1933. c. E. BENNETT 1,926,666

CONTINUOUS METAL PRESS Filed Feb. 1, 1932 2 Sheets-Sheet 2 A TTORNEYS.

Patented Sept. 12, 1933 1,926,888 co'N'rmUoUs METAL mass Charles E. Bennett, Hawthorne, N. 1., assig'lior to The Okonlte Company, Pascale, N. 1., a corporation of New Jersey Application February 1, 1932. Serial No. 590,000

11 Claims.

This invention relates to an improvement in metal presses, and has for one of its objects the provision of a metalpress such as a lead press,

* for instance, which can be continuously oper ated as distinguished from intermittent operation as in machines heretofore constructed.

A further object of my invention is the provision of an apparatus which is particularly well adapted for use in connection with the application of lead sheaths to cables, although it is to be understood that my apparatus is not to be confined to such use, and provides a construction whereby the sheathing operation can be carried on continuously to produce a sheath free of the usual annular line or zone of imperfect union.

In order that the advantages of my invention may be appreciated let me note that in lead presses, for instance, employed at the present time for cable sheathing, batch or intermittent operation is practiced, the apparatus being shut down after a run of from 100 to 200 feet of cable,

v for about ten minutes. The molten lead is supplied to the press from a lead pot and applied about the cable under high pressure. Owing to such intermittent operation 'the insulation of the cable in the die blocks is necessarily subjected, during stop periods, to temperatures varying from substantially 350 to 400 F. which is likely to cause gas pockets to form in the insulation, re-

sulting in faulty operation when the cable goes in service. At the end of a run in'the intermittent operation some lead remains in the dies and this lead has been subjected to tremendous pressure during the run and might be termed a wrought lead. The fresh lead (the next charge) must be welded to this wrought lead on the next run and I have found that a perfect joint can not be obtained. This may bedue to some changes in the molecular structure of the lead in the dies due to the tremendous pressure to which it has been subjected, or it may be due to the oxides and dross on the surface of this lead, or both, but'in any event imperfect joints appear in the sheath weakening the same. Such areas may not e visible on mere inspection with the result that when the cable goes into service' it breaks down at these areas and the cable may be drained of its oil.

The drawbacks above enumerated are overcome in the present invention in that'operation is continuous, the necessity of welds done away with, and a sheath homogeneous throughout produced.

In the accompanying drawings:

Fig. 1 is an elevational view with a part of the apparatus in section of an embodiment of my invention;

Fig. 2 is a longitudinal section through another form or embodiment of the invention; and

Fig. 3 is a view of a piece of sheathed cable capable of being produced by-my apparatus.

Referring first of all to the embodiment of my invention as illustrated in Fig. 1, in which I have shown a vertical machine, my improved apparatus comprisesa crosshead 1 mounted on suitable uprights or standards 2 and provided at its underside with a discharge spout 3.

4 and 5 designate the upper and lower sections of a lead press, this press containing a diefor forming a lead sheath about a cable which is continuously fed through the press.

,6 designates a crosshead suitably mounted on the uprights 2' and adapted to be raised by a. hydraulically operated piston '1.

8 designates a lead pot immediately above the In press sections 4 and 5 and in operation the piston or plunger 7 raises the'press and the pot 8 so that the discharge spout 3 enters the pot 8 to force lead in a molten condition to the dies in the press blocks 4 and 5 under pressure.

As above noted one of the objects of my invention is the provision of a lead press which may be continuously operated and in this connection I provide a melting pot 9 above the apparatus just described, this melting pot being 5 provided with a discharge conduit 10 which leads to a vertically extending rotary conveyor 11, the latter extending through the discharge nozzle 3. The melting pot 9 may be electrically heated by a coil 12 adapted to be connected to power mains.

13 designates a traveling conveyor, this conveyor extending vertically and having suitable arms 14 for receiving the lead ingots and dumping the same into shoot 15 which conveys the ingots into pot 9. V

The conveyor 11 is a screw conveyor and the pitch of the screw of this conveyor varies from a fairly long pitch at the upper end of the conveyor to a short pitch at the discharge end.

The conveyor 11 is driven by an electric motor 16 suitably geared to the conveyor.

' The spout or nozzle 3 is electrically heated by coils 1'7.

The press sections 4 and 5 are also electrically heated by coils 18 and 19, respectively. These coils may be connected to a source of power in the same manner as. illustrated in my co-pending application Serial No. 579,690 and provided with suitable switches and automatic controls as Shown in that application, thereby permittingthe press blocks to be preliminarily heated to a desired temperature and one or the other of the coils shut off and the frequency of the current supplied to these coils varied, all making for a saving in power consumption. However, these details are not a part of the present invention and as they are fully shown and described in my copending application above referred to I have not deemed it necessary to show these refinements in the present application.

. In operation lead ingots are supplied as necessary to the lead pot 9 by the conveyor 14 where they are reduced to a molten condition by the coil 12, the lead passing by the conduit 10 to the conveyor 11.

As the piston 'or plunger 7 is operated (the press blocks 4 and 5 having previously been heated up) to raise the pot 8, the initial pressure will be imposed on the lead, operation of the motor 16 thereafter causing the conveyor 11 to force the molten metal to the dies under the desired high pressure.

The apparatus is operated continuously, ingots being supplied to the pot 9 as frequently as may be necessary to maintain a supply of metal in the pot. Consequently after once beginning operation the present apparatus can be operated indefinitely to sheath cable of any length andto produce a sheath which not only has a uniform wall section but which is free of the usual annular line or zone of imperfect union produced by intermittent operation, as above pointed out.

In the embodiment of my invention shown in Fig. 2 I show a horizontal machine. 20 designates a lead pot which can be electr"cally heated by coil 20' ingots being supplied to the pot as necessary, so that the pot is kept charged at all times. This lead pot is provided with a discharge conduit 21 for conducting the molten metal to the interior of a conveyor housing 22 provided with a screw conveyor 23 the pitch of this screw varying from a long pitch at the end adjacent the discharge conduit 21 to a short pitch at the other end. The housing 22 of the conveyor is electrically heated by coils 24 and 25. Both of these coils may be automatically controlled, the coil 25 being shown as automatically controlled by a thermal couple 26 operating in a well known manner, being connected to thermal couple relay 27in turn adapted to control a contactor 28 connected to power mains. The provision of the coils 24 and 25 insures that the molten metal as it is advanced by the conveyor will be maintained at the proper temperature at all times.

The housing 22 adjacent the discharge end of the conveyor is provided with an outlet 29 permitting of the continuous discharge of lead from the housing to the dies shown at 30. The conveyor is driven by an electric motor 31 through proper gear reduction, and the pitch of the threads of the conveyor gradually shortening from the receiving end to the discharge end of the conveyor it will be obvious that the lead will be continuously supplied to the dies 30 at the desired high pressure.

It will be obvious that this apparatus provides a press adapted to be continuously operated to produce a sheath of uniform section and free of the usual annular line or zone of imperfect union.

If desired the block in which the dies 30 are mounted may be electrically heated in a manner similar to that shown in my co-pending application Serial No. 579,690 or as shown in Fig. 1.

In Fig. 3 I show a short length -of cable comprising conductor 32, insulation 33 and a lead sheath 34 applied thereto by the above described apparatus. Owing to the continuous operation of the press in applying the sheath 34, the sheath is free of the usual annular line or zone of imperfect union.

It will be apparent from the foregoing that I have provided a metal press adapted to be continuously operated, as distinguished from the batch operation heretofore necessary.

As above stated my invention is not to be limited to a press for handling lead as obviously other metals may be handled if desired.

It is to be understood, also, that the apparatus may be employed for purposes other than sheath- I wish to state also that in sheathing cables I for instance, a thin sheath of tin, for example, might be applied directly over the insulation by methods now known and practiced, my machine being employed to apply a lead sheath over this inner sheath.

What I claim is:

1. A press comprising in combination a die block, a pot providing a continuous supply of molten metal and a screw conveyor for continuously forwarding the molten metal from the pot to the die block under pressure, the pitch of said conveyor gradually and continuously diminishing in a direction toward the die block thereby imposing a gradually and continuously increasing pressure on .the molten metal.

2. A press comprising in combination a die block, a pot providing a continuous supply of molten metal and a heated screw conveyor for continuously forwarding the molten metal from the pot to the die block under pressure, the pitch of said conveyor gradually and continuously diminishing in a direction toward the die block thereby imposing a gradually and continuously increasing pressure on the molten metal.

3. A press comprising in combination a continuously driven screw conveyor, a housing for the conveyor, said housing being provided with an outlet to a die block, the pitch of said screw conveyor gradually and continuously diminishing in a direction toward the die block thereby imposing a gradually and continuously increasing pressure on the molten metal, a pot providing a continuous supply of molten metal, and a conduit for conducting the metal from the pot to the conveyor to be delivered thereby continuously to the die block.

4. A press comprising in combination a con-.

tinuously driven screw conveyor, a housing therefor, said housing being provided with an outlet to a die block, the pitch of said conveyor gradually and continuously diminishing in a direction toward the die block thereby imposing a gradually and continuously increasing pressure on the molten metal, a pot providing a continuous supply of molten metal, a conduit for conducting molten metal therefrom continuously to the conveyor to be delivered thereby continuously to the die block, and heating means for the pot and the conveyor- 1 5. A lead press comprising in combination a die block, a pot providing a continuous supply of molten metal, means for heating said pot, a screw conveyor the pitch of which gradually and con-' block under high pressure, heating means for the conveyor, and means for automatically controlling said last mentioned heating means.

6. A lead press comprising in combination a die block, a pot providing a continuous supply of molten lead, a screw conveyor the screw of which is of varying pitch diminishing in the direction toward the die block for imposing a gradually and continuously increasing pressure upon the molten lead fedthereto from said pot and for forcing the molten lead through the die block under high pressure, electric heating elements for said pot and said conveyor, and means for automatically controlling the heating element for the conveyor to maintain the molten lead at the proper temperature.

7. A lead press comprisingin combination a die block, a pot providing a continuous supply of molten lead, a screw conveyor the screw of which is of varying pitch diminishing in the direction toward the die block for imposing a gradually and continuously increasing pressure upon the molten lead fed thereto from said pot and for forcing the molten lead through the die block under high pressure, electric heating elements for said pot and said conveyor, means for automatically controlling the heating element for the conveyor to maintain the molten lead at the proper temperature, and means for raising said die block to impose initial pressure on the lead.

8. A soft metal press comprising in combination a continuously driven screw conveyor, a pot providing a continuous supplyof molten metal to said conveyor, a die block for receiving metal from said conveyor, the pitch of said conveyor gradually and continuously decreasing. in a direction toward the die block thereby imposing a gradually and continuously increasing pressure on the molten metal, a housing for said conveyor, a heating element carried by said housing for heating the molten metal in said conveyor, a heating element for said pot, and means for automatically regulating the heating element for the conveyor thereby to maintain the molten metal at the proper temperature during the continuous feeding of the same to the die block to provide a homogeneous product.

9. A press comprising in combination a heated melting pot providing a continuous supply of molten metal, a continuously driven screw conveyor, a conduit for conducting the molten metal from said melting pot to said conveyor, a housing for the conveyor, a heating element for said housing, a die block, said housing being provided with an outlet to said die block, the pitch of said conveyor gradually and continuously diminishing in the direction of said outlet to the die block, thereby imposing a gradually and continuously increasing pressure on the molten metal to force the metal through the die block under high pressure.

10. A press comprising in combination a continuously driven screw conveyor, a housing for the conveyor, means for heating said housing, a die block, said housing being provided with an outlet to said die block, a melting pot providing a continuous supply of molten metal to said conveyor, the pitch of said conveyor gradually and continuously decreasing in the direction of said outlet to the die block, means for continuously supplying ingots to said melting pot, and means for automatically regulating said heating means.

11. A soft metal press comprising in combination a melting pot, means for heating said melting pot, thereby to provide a continuous supply of molten metal, a screw conveyor, a heated housing therefor, means for conducting the molten metal continuously from the melting pot to said housing to be pushed therethrough by said conveyor, a die block adjacent the discharge end of said conveyor housing, said conveyor housing being provided with an outlet leading to the die block and disposed at an angle to the direction of travel of the metal through the said die block, the pitch of said screw conveyor diminishing in the direction of said outlet to the die block from the conveyor housing, thereby to force the metal through the die block under high pressures.

CHARLES E. BENNETT. 

